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1.
Sediment extracts from three polluted sites of the river Elbe basin were fractionated using a novel online fractionation procedure. Resulting fractions were screened for mutagenic, aryl hydrocarbon receptor (AhR)-mediated, transthyretin (TTR)-binding, and estrogenic activities and their potency to inhibit gap junctional intercellular communication (GJIC) to compare toxicity patterns and identify priority fractions. Additionally, more than 200 compounds and compound classes were identified using GC-MS/MS, LC-MS/MS, and HPLC-DAD methods. For all investigated end points, major activities were found in polar fractions, which are defined here as fractions containing dominantly compounds with at least one polar functional group. Nonpolar PAH fractions contributed to mutagenic and AhR-mediated activities while inhibition of GJIC and estrogenic and TTR-binding activities were exclusively observed in the polar fractions. Known mutagens in polar fractions included nitro- and dinitro-PAHs, azaarenes, and keto-PAHs, while parent and monomethylated PAHs such as benzo[a]pyrene and benzofluoranthenes were identified in nonpolar fractions. Additionally, for one sample, high AhR-mediated activities were determined in one fraction characterized by PCDD/Fs, PCBs, and PCNs. Estrone, 17β-estradiol, 9H-benz[de]anthracen-7-one, and 4-nonylphenol were identified as possible estrogenic and TTR-binding compounds. Thus, not only nonpolar compounds such as PAHs, PCBs, and PCDD/Fs but also the less characterized and investigated more polar substances should be considered as potent mutagenic, estrogenic, AhR-inducing, TTR-binding, and GJIC-inhibiting components for future studies.  相似文献   

2.
The effects of chrysene and the ozonated byproducts on in vitro gap junctional intercellular communication (GJIC) were evaluated using the scrape loading/dye transfer (SL/DT) technique. A 1 mM solution of chrysene was ozonated at dosages of 1.75, 3, 4.25, and 5 mol O3/mol chrysene (Chr). The early ozonation mixture, 1.75 mol O3/mol Chr, exhibited greater inhibition to GJIC than chrysene and irreversible damage to cells leading to cell death. To determine the compounds potentially responsible for the increase in toxicity, the byproducts formed upon treatment with 1.44 mol O3/mol Chr were separated into 14 fractions using RP-HPLC. The major compounds identified in the fractions were 2-(2'-formyl) phenyl-1-naphthaldehyde, 2-(2'formyl) phenyl-1-naphthoic acid, and 2-2-carboxyphenyl-1-naphthoic acid. 2-(2'-Formyl) phenyl-1-naphthaldehyde was determined to be the compound causing GJIC inhibition in sample fractions and byproduct mixtures.  相似文献   

3.
Samples of untreated groundwater from 1255 domestic drinking-water wells and 242 public supply wells were analyzed as part of the National Water-Quality Assessment Program of the U.S. Geological Survey between 1992 and 1999. Wells were sampled to define the regional quality of the groundwater resource and, thus, were distributed geographically across large aquifers, primarily in rural areas. For each sample, as many as 60 volatile organic compounds (VOCs), 83 pesticides, and nitrate were analyzed. On the basis of previous studies, nitrate concentrations as nitrogen > or = 3 mg/L were considered to have an anthropogenic origin. VOCs were detected more frequently (44%) than pesticides (38%) or anthropogenic nitrate (28%). Seventy percent of the samples contained at least one VOC, pesticide, or anthropogenic nitrate; 47% contained at least two compounds; and 33% contained at least three compounds. The combined concentrations of VOCs and pesticides ranged from about 0.001 to 100 microg/L, with a median of 0.02 microg/L. Water from about 12% of the wells contained one or more compounds that exceeded U.S. Environmental Protection Agency drinking-water standards or human health criteria, primarily because of nitrate concentrations exceeding the maximum contaminant level in domestic wells. A mixture is defined as a unique combination of two or more particular compounds, regardless of the presence of other compounds that may occur in the same sample. There were 100 mixtures (significantly associated with agricultural land use) that had a detection frequency between 2% and 19%. There were 302 mixtures (significantly associated with urban land use) that had a detection frequency between 1% and <2%. Only 14 compounds (seven VOCs, six pesticides, and nitrate) contributed over 95% of the detections in these 402 mixtures; however, most samples with these mixtures also contain a variety of other compounds.  相似文献   

4.
Methyl linoleate (MeLo) is a commercially available substrate widely used for studying the inhibitory properties of pure compounds and plant extracts against lipid oxidation. In this paper, 13 phenolic (benzoic and cinnamic acids, aldehydes and derivatives, and flavonoids) and other related compounds (butylated hydroxyanisole, butylated hydroxytoluene and tocopherols) as well as nine complex mixtures rich in phenolics (wines) or tocopherols (soybean oil extracts) were assayed for their inhibitory activity against MeLo autoxidation under mild conditions (40 °C, darkness and atmospheric pressure). Samples were also assayed for their free radical‐scavenging capacity against 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH?). Protocatechuic aldehyde, a compound that has not been previously evaluated by either of the two methods, showed the highest antioxidant activity. Some variations in the antioxidant ranking for some compounds were found between our results and those obtained by other authors using accelerated conditions for MeLo oxidation. Antioxidant activity of wines and soybean oil extracts was related to their richness in phenolics and tocopherols respectively. Correlation between antioxidant capacity measured by the MeLo and DPPH? methods was found for wines but not for the other samples studied. Therefore the measure of the free radical‐scavenging capacity of a compound is not always a reliable indicator of its lipid oxidation inhibitory ability. Copyright © 2004 Society of Chemical Industry  相似文献   

5.
Coastal sediments contain complex mixtures of hydrophobic compounds including organic contaminants such as polycyclic aromatic hydrocarbons and biogenic compounds such as cholesterol and phospholipids. Within the guts of benthic invertebrates, these mixtures are subjected to digestive, chemical conditions that can be rich in surfactants and proteinaceous material. Using in vitro incubations as proxy for digestive exposure, we studied the solubilization of binary mixtures of nutritional and contaminant lipids into artificial seawater and six marine invertebrate gut fluids (Molpadia intermedia, Cucumaria frondosa, Arenicola marina, Arenicola brasiliensis, Parastichopus californicus, and Nereis virens). For animals with surfactant micelles or high protein concentrations, solubilization interactions were frequent. For example, in Arenicola marina gut fluid, benzo(a)pyrene enhanced the solubilization of hexadecane (491% of the compound alone) and palmitic acid (130%) but hindered cholesterol (83%). Benzo(a)pyrene concentrations increased in gut fluids in the presence of cholesterol (137% of BaP alone), phenanthrene (154%), lecithin (140%), and hexadecanol (232%). In A. marina gut fluid, dilution with seawater indicated that these enhancements occur only when micelles are present. Sediment-water partitioning models, used to predict the bioavailability of hydrophobic organic chemicals, do not account for such interactions between solubilizates (compounds solubilized in micelles). However, for animals exposed via a digestive tract containing micelles or high protein concentrations, digestive bioavailability and perhaps bioaccumulation are likely influenced by these interactions.  相似文献   

6.
The polycyclic aromatic hydrocarbons (PAHs) naphthalene, acenaphthylene, acenaphthene, fluorene, fluoranthene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, ideno[1,2,3,-cd]-pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene and the polychlorinated biphenyls (PCBs) 8, 18, 28, 29, 31, 52, 77, 101, 105, 114, 118, 123, 126, 128, 138, 141, 149, 153, 156, 157, 163, 169, 170, 171, 180, 183, 187, 189, 194, 199, 201, 206, and 209 were measured in -200 rural soils across Great Britain (GB). Dominance of soil PAH profiles by heavier compounds (4-6 rings) provided initial evidence for the importance of source in governing soil PAH concentrations. No relationship was found between soil organic matter (SOM) and sum concentration of total and "heavy" PAHs, although there was a weak positive relationship with lighter compounds. A spatial statistical technique showed that highest soil PAH concentrations were usually found close to industrial/urban centers where presumably source intensity is highest. PCBs clustered into seven groups, five of which contained a single "dioxin like" PCB, one contained lighter congeners (2-4 chlorines), and one contained heavy congeners (5-10 chlorines). Linear regressions with SOM explained up to 24.3% of variation for the sum concentration of penta- to deca- congeners, but <1% for the lighter congener groups. No significant relationships were found with latitude. Spatial statistical techniques showed clusters of high soil PCB concentrations predominantly in west and south east GB, either associated with urbanized areas or on the West coast.  相似文献   

7.
In this study, adsorption and desorption of mixtures of organic compounds commonly emitted from automotive painting operations were experimentally studied. A mixture of two alkanes and a mixture of eight organic compounds were adsorbed onto beaded activated carbon (BAC) and then thermally desorbed under nitrogen. Following both adsorption and regeneration, samples of the BAC were chemically extracted. Gas chromatography-mass spectrometry (GC-MS) was used to quantify the compounds in the adsorption and desorption gas streams and in the BAC extracts. In general, for both adsorbate mixtures, competitive adsorption resulted in displacing low boiling point compounds by high boiling point compounds during adsorption. In addition to boiling point, adsorbate structure and functionality affected adsorption dynamics. High boiling point compounds such as n-decane and 2,2-dimethylpropylbenzene were not completely desorbed after three hours regeneration at 288 °C indicating that these two compounds contributed to heel accumulation on the BAC. Additional compounds not present in the mixtures were detected in the extract of regenerated BAC possibly due to decomposition or other reactions during regeneration. Closure analysis based on breakthrough curves, solvent extraction of BAC and mass balance on the reactor provided consistent results of the amount of adsorbates on the BAC after adsorption and/or regeneration.  相似文献   

8.
叶艳  苏伟  王倩  何欣  高静雅 《食品科学》2016,37(20):86-94
对接种发酵制作的豆豉香气成分进行分析检测,并与传统自然发酵豆豉和纯种米曲霉发酵的豆豉进行比较,经GC-MS分析,一共鉴定出了烃类、醇类、醛类、酮类、酸类、酯类、杂环化合物、含硫化合物、酚类以及其他化合物共10 类,152 种挥发性成分;结果表明,混合菌种发酵豆豉所含的烃类、醛类和酸类物质均高于纯种发酵培养,而传统自然发酵产生的醇类、杂环化合物、含硫化合物、酚类以及其他化合物都高于纯种发酵及混合菌种豆豉,而混合菌种发酵豆豉在酮类和酯类化合物要明显高于纯种米曲霉豆豉和传统自然发酵豆豉。  相似文献   

9.
Maurus Biedermann 《LWT》2006,39(6):647-659
The composition of two resoles based on cresol/phenol mixtures and of a resole manufactured from tert. butyl phenol were analysed by gas chromatography-mass spectrometry (GC-MS), comprehensive GC×GC, normal phase HPLC (NPLC) in combination with GC-MS and size exclusion chromatography (SEC). The cresol/phenol resin 2 contained perhaps 5000 components almost exclusively with methylene linkages between the rings. The resole from tert. butyl phenol largely consisted of components with 1-3 rings, about half of the linkages consisting of mono-methylene ether bridges. Comprehensive GC×GC provided the best picture of the sample composition, but the combination of NPLC with GC enables the most complete analysis.  相似文献   

10.
通过对以巴克夏和杜洛克猪为父本选育的猪肉中挥发性风味物质进行研究,了解不同品种猪肉之间挥发性 风味物质的差异,通过对猪肉中挥发性风味物质的评价为选育优质猪种提供参考。采用顶空固相萃取提取猪肉的 挥发性风味物质,并用气相色谱-质谱法检测风味物质,应用Origin 8.0软件和Xcalibur软件对实验数据进行分析,对 比猪肉中风味物质的含量差异及稳定性。结果表明:DLY系猪肉样品中共检测出38 种挥发性风味物质,其中醛类 13 种、呋喃类1 种、醇类6 种、酮类3 种、含硫化合物1 种、酸类14 种,DLY933猪肉样品中的正己醛相对含量最 高,达45.895%;SH451系猪肉样品中共检测出50 种挥发性风味物质,其中醛类25 种、呋喃类1 种、醇类9 种、酮 类2 种、含硫化合物1 种、酸类11 种,SH451-2猪肉样品中的正己醛相对含量最高,达75.986%;DLY和SH451系猪 肉样品共有的风味物质占15 种,SH451系猪肉样品的挥发性风味物质种类多于DLY系猪肉;SH451系猪肉样品的醛 类物质平均相对含量为74.68%,显著高于DLY系猪肉的57.47%,但DLY系猪肉样品的含硫化合物含量高于SH451系 猪肉,2 个猪种的风味各有特点。  相似文献   

11.
The combined estrogenic effects of mixtures of environmental pollutants in the in vitro ER-CALUX (chemical activated luciferase gene expression) bioassaywere examined to biologically validate a sample preparation method for the analysis of estrogenic compounds in sediment. The method used accelerated solvent extraction (ASE) and gel permeation chromatography (GPC) and was validated with respect to recovery of biological response taking mixture effects into account. Four mixtures of three to six xenoestrogenic compounds (bisphenol A, 4-nonylphenol, (4,4'-dichlorodiphenyl)trichloroethane, (2,4'-dichlorodiphenyl)trichloroethane, dieldrin, 4-n-octylphenol, alpha-chlordane, dibutylphthalate, (4,4'-dichlorodiphenyl)dichloroethylene, and 2,4,5-trichlorobiphenyl) were prepared. Experimentally determined mixture effects were well described by the concept of concentration addition (CA), as expected for similarly acting compounds. Observed estradiol equivalence factors of the mixtures (on average 1.2 +/- 0.3) agreed very well with the value predicted according to CA. The sample preparation method was then applied to pure mixtures of standards and to sediment spiked with one of the mixtures. Recoveries of estrogenic compounds were estimated by determination of their mixture potencies in ER-CALUX and compared to the mixture effects predicted by CA. Recoveries of estrogenic activity were between 80 and 129%, indicating that the additive behavior of mixtures of xeno-estrogens is well conserved during sample preparation. Together with an average repeatability of 18.3%, low average limit of detection (2.6 +/- 1.8 pg of EEQ/ g), and coefficient of variance (3.5 +/- 3.3%),this demonstrated the suitability of the sample preparation method for the analysis of mixtures of (xeno-)estrogenic compounds in sediment with the ER-CALUX assay.  相似文献   

12.
Four barley cultivars were grown in replicated trials at three sites in Scotland in 2000, both as pure stands and in all four possible three‐component mixtures. After harvest, some grain from the pure stands was used to synthesise four blends of three component varieties. Grain from the pure stands, the mixtures and the blends was malted and all samples were assessed for total β‐glucan content. At two of the sites, field grown mixtures were shown to have lower malt β‐glucan than blends made prior to malting, although their grain β‐glucan contents had not been significantly different from the means of the component varieties. At the other site, the mixtures had higher levels of soluble nitrogen than the blends or the means of their component cultivars although, significant differences had not occurred in grain nitrogen contents. Three component blends were also made from the malted grain of the pure stands and hot water extracts were measured on all samples including the blends made before and after malting. There were considerable differences between sites and also between mixtures, blends and the mean of the mixture components when assessed separately. At all sites and for all varietal combinations, field grown mixtures were shown to be equal or superior to blends made after harvesting, in addition to frequently exceeding the mean of their components. It was concluded that the advantages, in β‐glucan or protein modification, associated with mixtures resulted from interactions between components in the growing environment and that interactions in the malting and mashing environments had little if any effect.  相似文献   

13.
炭疽病是影响香蕉采后货架寿命限制因子。为了寻找国家标准允许使用的控制香蕉采后炭疽病的方法,从腐烂香蕉上分离炭疽病菌,并进行鉴定。对纯水中炭疽病菌添加消毒剂和臭氧进行处理,在培养基上分别添加多种食品防腐剂、消毒剂和臭氧处理,抑制该菌孢子的萌发和菌丝的生长,筛选出抑制效果好的处理。对香蕉用所选防腐剂、消毒剂和臭氧处理进行保鲜试验,结果发现3 mg/kg的桂醛、50 mg/kg的戊二醛、10 mg/kg的二氧化氯、10 g/h臭氧处理对纯水中炭疽病菌的消毒效果很好,但对培养基上炭疽病菌消毒效果不好。0.24%亚硫酸氢钠可以完全抑制炭疽病孢子萌发,且对炭疽病菌丝生长抑制作用最强。12 mg/kg对羟基苯甲酸乙酯有较强的抑制炭疽病孢子萌发和菌丝生长作用。山梨酸钾、双乙酸钠、苯甲酸钠、脱氢醋酸钠、丙酸钙对香蕉炭疽病菌抑制效果较差。10 g/h臭氧处理香蕉10 min,12 mg/kg对羟基苯甲酸乙酯洗果3 min,与500 mg/kg多菌灵抑菌效果类似,消毒处理均显著好于对照。先臭氧处理或戊二醛、桂醛、二氧化氯处理,后对羟基苯甲酸乙酯处理,可以控制香蕉炭疽病,延长香蕉货架寿命。  相似文献   

14.
The authors have developed a method for determining the volatile oil content of onions. Using this method they found in the Hungarian Makó onions 0.019—0.031 % volatile oil, depending on storage. The composition of onion oil was studied by GC; GC-MS and TLC methods. GC-MS revealed 20 volatile sulphur compounds identified as 10 trisulphides, 6 disulphides, 3 tetrasulphides, and 1 thiophene derivative as well as one unsaturated aldehyde. Three of these: ethyl cis-1-propenyl trisulphide, ethyl trans-1-propenyl trisulphide, and butyl methyl trisulphide were described for the first time in onions. Carbonyl compounds were studied in the form of derivatives obtained with 2,4-dinitrophenyl hydrazine. On the basis of Rf-values and by addition, propanal, butanal, pentanal and hexanal were identified in the aldehyde fraction, while in the dicarbonyl fraction — beside an unknown compound — glyoxal and methyl glyoxal were identified. The presence of these two compounds in onion oil has been reported for the first time.  相似文献   

15.
Humic substances originated from aquatic, soil, or sediment environments are mixtures of humic compounds with various characteristics. Sorption interactions with isolated, well defined humic fractions can be studied either in an aqueous phase ("dissolved humic substances"), or in a solid-phase, by coating mineral particles with the humic materials, or simply by working with humic acid particles (powder) at low pH to minimize dissolution. Each attitude, by definition, can be studied by different experimental techniques and has a different meaning for understanding natural environmental processes. In this study, a new tool for studying sorption interactions is presented. Sol-gel was used as an inert matrix to immobilize (entrap) various humic acids (HAs), and then used to study the interactions of several polycyclic aromatic hydrocarbons (PAHs) with the entrapped HA. Linear and nonlinear sorption coefficients were highly correlated with contaminant hydrophobicity. Sorption of pyrene to immobilized HA was in the order of soil HA > Aldrich HA approximately = peat HA. It was concluded that the entrapped HAs retained their original properties in the gel matrix and were accessible to the external contaminant through the pore network. Additionally, binding coefficients of pyreneto dissolved humic substances and to dissolved organic matter (DOM) were determined from the reduction in pyrene sorption to immobilized HA in the presence of dissolved humic material or DOM in solution. Binding coefficients of pyrene were in the order of the following: dissolved Aldrich HA > dissolved peat fulvic acid (FA) > DOM derived from mature compost > DOM derived from fresh compost.  相似文献   

16.
以苹果木烟熏液为研究对象,从感官品质、pH值、羰基化合物、酚类化合物、苯并(a)芘的含量、挥发性风味物质的组成和电子鼻分析等角度研究苹果木烟熏液的性质,并与目前市场上烟熏液产品进行比较。结果表明,苹果木烟熏液pH值为2.31,酚类化合物、羰基类化合物的含量分别达到9.94 mg/mL和7.91 g/100 mL,挥发性风味物质以酚类物质和醛类为主,相对含量分别为36.15%和17.58%,通过电子鼻主成分分析发现,苹果木烟熏液与其他几种烟熏液之间主成分有显著性差异,与市场其他烟熏液相比,在核心成分和特征性风味物质均有明显的优势,同时无苯并(a)芘检出,表明苹果木烟熏液具有良好的应用前景。  相似文献   

17.
为探究木瓜蛋白酶对马肉挥发性风味物质的影响,采用顶空固相微萃取(HS-SPME)结合气相质谱联用(GC-MS)法对马肉的挥发性风味物质进行鉴定,通过计算风味物质的相对气味活度值(ROAV)确定其关键风味成分。结果表明,空白组检出30种风味物质,木瓜蛋白酶处理组检出25种风味物质,表明马肉经过木瓜蛋白酶处理后,挥发性风味物质种类减少,但是醛类风味物质的相对含量(68.56%)明显提高。空白组和木瓜蛋白酶处理组的共有关键性风味物质种类的差异不大,醛类物质是马肉典型的风味物质,辛醛、壬醛、癸醛和戊醛对马肉的风味均有较大贡献,3-甲基丁醛对木瓜蛋白酶处理组的风味贡献很大,ROAV为93.03。  相似文献   

18.
Influence of sequential yeast mixtures on wine fermentation   总被引:3,自引:0,他引:3  
The use of Pichia fermentans in pure cultures and sequential mixtures with Saccharomyces cerevisiae has been studied to improve the aromatic compounds and characteristics of a wine. P. fermentans has proved to be a good starter strains for must fermentation in the winemaking industry. It has shown the same level of sulphur tolerance and the same growth rate as S. cerevisiae. We have demonstrated that only 2 days of must fermentation with P. fermentans in sequential mixtures are enough to increase the following compounds in the wine both qualitatively and quantitatively: acetaldehyde, ethyl acetate, 1-propanol, n-butanol, 1-hexanol, ethyl caprilate, 2,3-butanediol and glycerol. Maintaining this non-Saccharomyces strain in contact with the must for longer periods quantitatively increases the flavour composition.  相似文献   

19.
2-Biphenylol, 3-biphenylol, 2,2'-biphenyldiol, 3,3'-biphenyldiol, 3-chloro-2-biphenylol, and 4,4'-dichloro-3-biphenylol were evaluated using the scrape-loading/dye transfer (SL/ DT) technique to determine in vitro gap junctional intercellular communication (GJIC) in a normal rat liver epithelial cell line as a measure of the epigenetic toxicity. Cytotoxicity was determined using the neutral red uptake assay. A dose range of 0-300 microM was examined. Only 3,3'-biphenyldiol and 4,4'-dichloro-3-biphenylol induced cytotoxicity within the tested dose ranges. Noncytotoxic doses were selected for evaluation of epigenetic toxicity. 4,4'-Dichloro-3-biphenylol was most inhibitory to GJIC at the lowest dose. The cytotoxicity and GJIC inhibitory effects observed for 4,4'-dichloro-3-biphenylol might be, although not exclusively, a consequence of the lipophilic nature of this chemical. 3-Chloro-2-biphenylol was least inhibitory to GJIC. 3-Chloro-2-biphenylol was less inhibitory to GJIC than 2-biphenylol because of the presence of the chlorine functional group, which appears to attenuate the toxic effect of the ortho-hydroxyl group. Although cells were capable of complete recovery of GJIC after removal of each of the chemicals, only with 2,2'-biphenyldiol and 4,4,'-dichloro-3-biphenylol did the cells demonstrate partial recovery without removal of the chemical. The more noncoplanar conformation of 2,2'-biphenyldiol and 2-biphenylol might explain their more inhibitory behavior in comparison to 3,3'-biphenyldiol and 3-biphenylol, respectively.  相似文献   

20.
研究了九香虫的防御性物质水溶液中挥发性成分及其相对百分含量,以及该水溶液对人肝LO2细胞活性的研究。采用温水浸泡法获得九香虫的防御性物质水溶液;GC-MS获得该水溶液的挥发性成分组成,并用面积归一法计算各成分的相对百分含量;利用MTT法、流式细胞术研究该水溶液对LO2细胞的影响。研究表明,九香虫防御性物质水溶液中挥发性成分包含19种化合物,其中相对百分含量最高的为反-2-己烯醛(88.54%),其次为2-甲基-4-戊烯醛(5.16%)、十三烷(3.43%)等;该水溶液作用LO2细胞后,IC50为3.64 μL,呈剂量依赖性;细胞周期结果显示,G2/M期细胞比例明显降低,而G0/G1期细胞比例明显升高,且差异具有统计学意义。九香虫防御性物质水溶液成分主要是烯醛和烷烃类化合物;该物质能够抑制人肝LO2细胞的体外增殖,可能与其细胞周期阻滞有关。  相似文献   

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